The present disclosure generally relates to adhesion promoters comprising a silane composition admixed with an aqueous buffer solution, where the silane composition comprises at least two hydrolytic silane compounds, and the use of such adhesion promoters in methods for promoting adhesion of adhesives to a substrate. In embodiments, the adhesion promoter may be used in a hot melt adhesive or a pressure sensitive adhesive that is to be applied to a substrate.
The addition of the adhesion promoter to hot melt adhesives or pressure sensitive adhesives improves adhesion to very low surface free energy substrates. The admixed silane composition with aqueous buffer solution improves the thermal stability of the adhesive and the viscosity of the adhesive remains relatively constant at temperatures, for example, ranging from about 100° C. to about 200° C. The adhesive containing the admixed silane adhesion promoter is thus able to bind very low surface free energy substrates such as Xerographic prints contaminated with fuser oil, and maintains a substantially stable viscosity at adhesive application or operating temperatures from about 100° C. to about 200° C.